 /*******************************************************************************
  * Copyright (c) 2005, 2006 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/epl-v10.html
  *
  * Contributors:
  * IBM Corporation - initial API and implementation
  *******************************************************************************/

 package org.eclipse.core.commands;

 /**
  * <p>
  * An object that holds zero or more state objects. This state information can
  * be shared between different instances of <code>IObjectWithState</code>.
  * </p>
  * <p>
  * Clients may implement, but must not extend this interface.
  * </p>
  *
  * @see AbstractHandlerWithState
  * @since 3.2
  */
 public interface IObjectWithState {

     /**
      * Adds state to this object.
      *
      * @param id
      * The identifier indicating the type of state being added; must
      * not be <code>null</code>.
      * @param state
      * The new state to add to this object; must not be
      * <code>null</code>.
      */
     public void addState(String id, State state);

     /**
      * Gets the state with the given id.
      *
      * @param stateId
      * The identifier of the state to retrieve; must not be
      * <code>null</code>.
      * @return The state; may be <code>null</code> if there is no state with
      * the given id.
      */
     public State getState(String stateId);

     /**
      * Gets the identifiers for all of the state associated with this object.
      *
      * @return All of the state identifiers; may be empty, but never
      * <code>null</code>.
      */
     public String [] getStateIds();

     /**
      * Removes state from this object.
      *
      * @param stateId
      * The id of the state to remove from this object; must not be
      * <code>null</code>.
      */
     public void removeState(String stateId);
 }

